See background information here.

In the Harmonious Republic of Mars, the finest forms may be found of any and all luxuries available in the Solar system. This includes moving pictures. Only in the Harmonious Republic does mankind watch, rather than read, the news. And in color!

With blasphemous computers banned for all time, these television devices were thought to be relegated to the history books. But through decades of dedicated work in the Bureau of Public Entertainment, a new style of moving picture screen was developed, so that in all public spaces a person might be able to follow the pronouncements of the Supreme Council of Harmony or any other part of the Harmonious Bureaucracy.

For those honored to be members of the Harmonious Cohort, a moving picture screen in the home is even possible. Indeed, life is good here on the Red Planet.


The GE Porta-Color is the last all CRT color television made in the US. Given that computers are banned, and given all current and plausible near-future technology, what advances could be made over the Porta-Color? How high of a definition could TV screens in public places (not necessarily affordable for a private home) have?


  • Computers are banned. Thinking about a computer will get you burned at the stake. Therefore, people don't think about making computers.

  • For the purposes of the question, anything that has electronic memory is a computer. Anything that has software that can be programmed is a computer. Anything that was ever historically considered to be an electronic computer is a computer.

  • An electric calculator has electronic memory and is a computer. Slide rules and nomographs are examples of mechanical 'computers' that have no memory other than their current state; they are not computers.

  • The GE Porta-Color is not programmable and has no memory, therefore it is not a computer. Any ASIC that can be cost effectively designed entirely by hand (and doesn't have any memory, and is not programmable) is not a computer.

  • Transistors, and thus LEDs, are not banned. Whether you could develop LEDs without betting burned at the stake is another matter.

  • All materials available at the present day will be available in the Harmonious Republic, unless those materials cannot be created without a computer.

  • Plausible near-future technology means something where most of the engineering problems have been solved and the only remaining obstacles are refinement or cost or culture.

  • For example, universal smart glasses are plausible near-future technology, fusion power is not. Self-driving cars would be plausible too, except those would definitely get you burned at the stake.

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    $\begingroup$ Comments are not for extended discussion; this conversation has been moved to chat. $\endgroup$
    – James
    Jan 5 '18 at 19:55
  • $\begingroup$ Can I just say that all considerations are just "Computers are banned", and then elaborate on how they are banned $\endgroup$ Nov 6 '18 at 14:31

News Reels

Film, the original analog video material, far exceeds any modern HD standard. 35mm film was the standard for movie theaters from the 1920's until recently when digital projectors became common, and a 35mm negative is estimated to be around 87 megapixels, or over 10x 4K resolution. IMAX 70mm film would have over 720 megapixels.

With fast transit, half the circumference of earth with no oceans, film reels could be delivered to the opposite end of Mars in 12 hours if carried at 500 mph. So, news is filmed in the morning, duplicated, then shipped across the planet by evening. Small projectors could be used in homes, large projectors could be used in theaters or public displays.

  • $\begingroup$ I like this thought. A lot of TV programming was broadcast from film 'scanning' on the fly in the early days before magnetic recording. $\endgroup$
    – KalleMP
    Jan 6 '18 at 17:01
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    $\begingroup$ On Photography.SE the consensus seems to be 15-25 Mpixels, not 87. $\endgroup$
    – Nick T
    Jan 6 '18 at 20:10

There really isn't a limit, other than some mild limits for synchronization. "High definition" in public places, where there's few size limitations, "high definition" is more marketing speak than anything.

The trick is to build a composite screen out of many smaller screens. This is how all big screens are manufactured. Instead of trying to make some extremely powerful CRT with 40k lines (well, 20k interlaced, of course), you make a huge display that is 80 screens tall, each one with 500 lines, which was doable in the pre-computer era.

Many-screens together

As for what advances could be made, a serious question would be what advances are needed? Size and weight were the main limiting factors for a CRT. Kingledion provides an answer which suggest that plasma screens could be possible to deal with these issues. But the real question is "what advances are the members of the Harmonious Republic interested in?" That is likely not the same thing we will be interested in. With computers, we can always take the "more is better" approach, but that is not as popular without computers to sort the data for us. I would presume that they would not be impressed by a 16MP camera on a cell phone, just because it has a higher number of pixels than the 2MP camera they have already.

With the name "Harmonious Republic," they might want to give some lip service to the concept of "harmony." I think they might be interested in having screens that adjust their color balance and brightness to blend in with the environment a bit more. Advanced glass blowing might let them design TVs that work around unusual shapes rather than having to make everything square. But that's just me.

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    $\begingroup$ Then put this screen far away to make it look small. $\endgroup$
    – wizzwizz4
    Jan 5 '18 at 18:01
  • $\begingroup$ I was going to answer with something like this, but I couldn't word it very well, so I abandoned it. This answer is much better worded than my attempt. I was also going to suggest shrinking the size of the pixels, like the industry currently does. $\endgroup$ Jan 5 '18 at 18:08
  • $\begingroup$ But this really isn't "high definition", it's just more screen area. Really the only limits are imposed by the analog frequencies at which your signal is broadcast, and if you multiplexed the signal on multiple frequency bands, you could get very high definition. But the question might get better answers if asked on the Electronics site. $\endgroup$
    – jamesqf
    Jan 5 '18 at 19:21
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    $\begingroup$ @jamesqf I think we have to admit that "high definition" is just a marketing term, devoid of all useful technical meaning. $\endgroup$
    – Cort Ammon
    Jan 5 '18 at 19:48
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    $\begingroup$ +1 for Big Buck Bunny in the right display :) $\endgroup$ Jan 5 '18 at 22:57

This is an answer to Revision 3 of the question, please judge accordingly.

No limit

Given your restriction:

Computers are banned. Thinking about a computer will get you burned at the stake. Anything that approaches Turning complete, other than a human brain, is considered a computer.

and given that OpenGL shaders (model 1 and 2) was never even close to being Turing complete, you are good to go. Later models were closer to Turing completeness because games required it. No need for arbitrary iteration processing when all you want is video codec.

Similarly, UDP-like networking does not need loops, and can be easily implemented in a non-complete way. For media stream, some dropped frames are no concern.

That said: your video can be as high definition as you like it, using high-tech electronic than in terms of performance does not need to be any weaker than modern tech, and can indeed be designed in a turing-incomplete way.

GPIB bus didn't require turing-complete computer hardware. It worked fine for scientific electronics significantly more limited. Similarly, scientific calculators with graphic display was not fully programmable, but could be nearly as powerful as computers of their time (nearly because there was no need for more). Advanced electronic could be developed in parallel with computers without being computers. We stopped advancements only because computers were cheaper.

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    $\begingroup$ I think you are being pedantic. I don't have the time to develop an algorithmic definition of what a computer is. I'm pretty sure my question is clear enough. Suggesting that OpenGL shaders and UDP networking could be developed ex nihilo without other computing resources is similarly silly. This answer does not meet the spirit of the question. It is basically just trolling, especially if you close voted as well. $\endgroup$
    – kingledion
    Jan 5 '18 at 14:30
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    $\begingroup$ You mention in the comments to the question that this is not answerable and at the same time you answer it. Which is it? It's very confusing, especially for newer users who might see this, to see someone with such a high reputation display such contradictory behaviour. It reminds me of the discussions about How should we handle cases where people VTC and answer or answer with a VTC reason at the beginning? $\endgroup$
    – Secespitus
    Jan 5 '18 at 14:43
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    $\begingroup$ @Secespitus, I'm amused by your link, especially who wrote and edited the top answer. Please sort it between you. $\endgroup$
    – Separatrix
    Jan 5 '18 at 14:47
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    $\begingroup$ I fail do understand why people in the comments think, you'd need computers to design a TV. $\endgroup$ Jan 5 '18 at 15:34
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    $\begingroup$ Whomever flagged this answer as low-quality needs to have their head examined. "Low quality" has nothing to do with right or wrong. Molot's answer clearly meets our expectations for quality. If you think it fails to answer the question, downvote it. "Low quality" means the answer is so insufficient in its construction (whether the answer is wrong OR right) that it can't be saved without beating the answerer with a stick. A one-line answer or an answer that depends on a link without providing a summary, those are quality issues. Read the FAQ for more info. $\endgroup$ Jan 5 '18 at 16:34

Plasma screens are possible

The technology underpinning plasma display has little to do with the motive force behind it. In a cathode ray tube (CRT) television, an electron gun scans across the phosphorescent screen in a raster pattern. There are three electron beams, one for each color red, green and blue.

For a plasma display, the same setup could be used except that instead of three beams illuminating the phosphorescent screen of a CRT, the electron gun would activate invividual plasma cells. These cells are basically tiny fluorescent lights, with gasses and interior coating designed to emit the three primary colors.

Going with this design will save power by reducing the number of electron guns, remove the CRT will allows better scaling to larger sizes. It will also allow much higher contrast ratios. Where CRT pictures are limited by the activation of the phosphorous screen, the individual plasma cells can activate and shut off more quickly, giving better response times and higher possible frame rate.

With the same circuitry demodulating whatever the desired picture signal is, a plasma display will allow better picture quality.

  • 1
    $\begingroup$ How will you build the machines to build the plasma screens as surely as the machines used to build them would be computers? (and/or other advanced tech, anything with RAM is a computer) $\endgroup$
    – cybernard
    Jan 5 '18 at 22:22

You forgot about the 1080i CRT analog TVs from Japan!

enter image description here

"Japan had the earliest working HDTV system, with design efforts going back to 1979."

Silly Americans ;)

They can easily get up to 1080i. For the following example I checked the manual and all the inputs are analog. Sure there's some computer stuff in it like all TVs have but if you're asking "can you make a high def CRT TV" The answer is YES! Japan had been broadcasting analog HD signal for a long time at 1035i. Source

PS: Lets also talk about projection TVs for a moment.

Because, there's no need to limit yourself to CRTs.

enter image description here

(Source) How is this BestBuy link not dead yet



PPS: I imagine that if CRTs were not abandoned, some day they could get them up to 4k. I'm not knowledgeable enough to say that. Someone please correct me in the comments.


With analogue TV, there are no hard limits. CRT's have no inherent horizontal resolution, the limit is the size of phosphorus atoms and the colimation of the beam, and the quality of picture is given by frequency bandwidth of the signal (this is valid for B&W TV, colo(u)r introduces complications in the form of a discrete mask). Vertical resolution equals the number of lines, and that is limited by bandwidth.

French 819 line (737 lines visible) standard had a bandwidth of 14 MHZ (in VHF band no less), and that is 1940s technology - no computers necessary at all. Japan's MUSE had 1125 lines (1035 visible) took 20 MHz, with some tricks squeezed to 8 MHz channel. European HD-MAC was similar - and that's early 1980s technology. (note that all of these are interlaced standards)

If you move to gigahertz frequencies, you have enough bandwidth for many multiplies of this - and that's still analogue, no computers nor even DSP needed. However, you soon run into problems with designing gigahertz circuits and producing your TV sets in sufficient quality and tolerances without computers in the design and production lines. This might be of no issue if the components or the whole TV sets are imported.


Display isn't computing, so Mars' laws can be dismissed as irrelevant. Individual policemen may argue that anything at all is a computer, but if it's the government putting these things in place, then the law matters, and those policemen's opinion does not.

So on the face of it, the question can be simplified to one of various questions about electronics, suitable for electronics.se rather than worldbuilding.se.

1) If the question can be reduced to "what're CRT's resolution/size limits?" then the ViewSonic P225f was 2048x1536. Some online sources claim 2560x1920, but I suspect this was processing resolution, not display resolution.

[Aside: while max display resolution and max processing resolution do not always match up, it is important to blithely ignore any people who claim that color CRTs lack an inherent native resolution, or in any way lack pixels. They are either confusing them with analog monochrome CRTs, are unaware of how the technology worked, or are using their own incorrectly nitpicky definitions of jargon terms like 'pixel' in order to try to be argumentative or look smart.]

CRTs, because of the glass used around the sides of the tube, inherently mean big gaps in video walls, so you're limited by the max size of one "screen".

These gaps can be ameliorated entirely with projection and compensation (at the cost of brightness), or with lenses (assuming the viewing angle is correct).

2) Perhaps instead the question can be reduced to "what're the resolution/size limits of non-digital displays?"

After all, restricting to CRT makes little sense in terms of "computing". LCD, LED, etc are also non-computing, and can at least in theory make a video wall with no (or, negligible) gaps. A couple of mm at most.

http://en.wikipedia.org/wiki/Analog_television may be a helpful resource: analog transmission and processing is limited mainly by bandwidth. Transmitting the signal over cable can entirely remove that limit, meaning that with enough cables, you could have an entire IMAX sized wall displaying video at 0.2mm dot pitch.

That would be a fairly epic challenge, though. First, you'd need a camera that could capture it... but IMAX has shown this is possible on celluloud, which is analog. Then you'd need to split each celluloid image up into signals for many "little" screens, and transmit the signal for each mini-screen on the wall.

3) But I think what the question actually meant "what're the resolution/size limits of displays that use no integrated circuits" particularly given the example given: the Portacolor was US' last valve TV produced, not the last CRT TV.

However, this still reduces to one of the two earlier options, as valves became redundant only due to their size, power requirements, cooling requirements, cost, unreliability, and other flaws. Their switching speed and other capabilities were never the issue, and were improving as constantly as ICs have. Moore's law was invented before Integrated Circuits.

But this is Worldbuilding.se. So we have Worldbuilding concerns. So this IS a Worldbuilding question.

So perhaps instead the question can become: "are there things that would decide one way or the other between those two options? That could either permit or forbid LEDs (diodes are semiconductors), LCDs, and plasma screens?"

That depends on the terms of the law, and that falls very firmly into the realm of Worldbuilding.

Say the law came about because an Artificial General Intelligence nearly wiped out humanity, causing everyone to have to flee to Mars.

So, obviously, the police and public will understand the law as "no computers", since that's the easiest way to explain it to laymen, but what actually is forbidden is some blahblah legalese fine print that prevents AGI from being redeveloped.

In that case, the law may be written to prevent use of semiconductors, which would prevent any realistic kind of AGI-capable computer. This would also prevent LEDs and OLEDs, but permit plasma and LCD.

Or it could be written about the processes used to create them: no photolithography, perhaps. This would make any of these technologies difficult or just completely impossible, other than the CRT.

Or it could be written to prevent digital electronics - again, this would limit things pretty much to the CRT.

In these latter two cases, you'd be stuck with CRTs and valves as the standard technology, which means that you get to use nixie tubes, which means that you've won the internet even in a universe with no internet.

You win yourself a lovely retrofuturistic technopunk world. People might wear disabled ICs as jewelry in the same way that steampunks wear cogs.

  • $\begingroup$ Just for clarification, aren't valves and CRTs both just vacuum tubes? Maybe I should have said: the last all vacuum tube TV. $\endgroup$
    – kingledion
    Jan 5 '18 at 22:09
  • $\begingroup$ Also the early computers were made with valves so that is not enough to prevent AI proliferation or at least simple computing. I think it would make more sense to move to a planet with rust on the ground instead of silicon oxide to minimise the proliferation of the silicon microelectronic industry. Ooops, that has already been done by OP so I think the battle is won and the AIs nanobot factories cannot take hold on the Red Planet. $\endgroup$
    – KalleMP
    Jan 6 '18 at 17:06
  • $\begingroup$ @KalleMP Tubes are inherently BIG. An AGI computer made with valves would be the size of a planet, with cooling systems the size of several suns, requiring several more suns just for power. By the time it became a problem, I suspect the law could have been tweaked. :) $\endgroup$ Jan 6 '18 at 18:44
  • $\begingroup$ @kingledion Yup! Well, tubes, at least: not all vacuum-filled, some filled with inert gasses. $\endgroup$ Jan 6 '18 at 18:47

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